Four-stroke engines generate less pollution and use less fuel than two-stroke engines do so that more and more small power tools such as mowers, trimmers, chain saws, or even remote control model engines use four-stroke engine as the power supply. These power tools are operated at different angles so that all the parts of the engines have to well lubricated when operation. A special designed lubrication device is needed to provide proper lubrication. The conventional way is to moisturize the lubrication oil so that the moisturized lubrication oil can flow to every part of the engine.